/**
 * A JavaScript implementation of MD5, as defined in RFC 1321.
 *
 * useage: var md5 = MD5.encrypt("to_be_encode"); 
 *
 * @package js.crypto
 * @Copyright (C) 2006-2007 Ma Bingyao <andot@ujn.edu.cn>
 * @author: DSONet (dsonet@msn.com)
 * @version $Id: MD5.js 35 2008-03-02 17:01:34Z dsonet $
 */
var outputTypes =
{
	//Enumeration for input and output encodings.
	Base64 : 0, Hex : 1, String : 2
};
var MD5 = function() {
	var charSize = 8, mask = (1 << charSize) - 1;
    function add32(x, y) {
        var lsw = (x & 0xFFFF) + (y & 0xFFFF);
        var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
        return (msw << 16) | (lsw & 0xFFFF);
    }

    function bitrol(n, c) {
        return (n << c) | (n >>> (32 - c));
    }

    function cmn(q, a, b, x, s, t) {
        return add32(bitrol(add32(add32(a, q), add32(x, t)), s),b);
    }

    function ff(a, b, c, d, x, s, t) {
        return cmn((b & c) | ((~b) & d), a, b, x, s, t);
    }

    function gg(a, b, c, d, x, s, t) {
        return cmn((b & d) | (c & (~d)), a, b, x, s, t);
    }

    function hh(a, b, c, d, x, s, t) {
        return cmn(b ^ c ^ d, a, b, x, s, t);
    }

    function ii(a, b, c, d, x, s, t) {
        return cmn(c ^ (b | (~d)), a, b, x, s, t);
    }

	function toStr(b) {
        for (var l = b.length << 2, s = new Array(l), l = l * charSize - charSize; l >= 0; l -= charSize) {
            s[l/charSize] = String.fromCharCode((b[l >> 5] >>> (l % 32)) & mask);
        }
        return s.join("");
    }

	function toHex(b) {
		for(var i = b.length*4 - 1, s = new Array(i + 1), h="0123456789abcdef"; i >= 0; i--){
			s[i] = (h.charAt((b[i >> 2] >> ((i % 4) * 8 + 4)) & 0xF) + h.charAt((b[i >> 2] >> ((i % 4) * 8)) & 0xF));
		}
		return s.join("");
	}

	function toBase64(b){
		for(var p = "=", tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
			, i = b.length * 4 - 1, n = Math.ceil((i + 1) / 3) * 4, s = new Array(n), j, t; i >= 0; i -= 3){
			t = (((b[i >> 2] >> 8 * (i % 4)) & 0xFF) << 16) | (((b[i + 1 >> 2] >> 8 * ((i + 1) % 4)) & 0xFF) << 8) | ((b[i + 2 >> 2] >> 8 * ((i + 2) % 4)) & 0xFF);
			for(j = 3; j >= 0; j--){
				s[--n] = i * 8 + j * 6 > b.length * 32 ? p : tab.charAt((t >> 6 * (3 - j)) & 0x3F);
			}
		}
		return s.join("");
	}

    function toBin(s) {
        for (var l = s.length, b = new Array(l), l = l * charSize- charSize; l >= 0; l -= charSize) {
            b[l >> 5] |= (s.charCodeAt(l/charSize) & mask) << ((l % 32));
        }
        return b;
    }

	function core (x, len)
	{
		x[len >> 5] |= 0x80 << ((len) % 32);
		x[(((len + 64) >>> 9) << 4) + 14] = len;

		var a =  1732584193
			, b = -271733879
			, c = -1732584194
			, d =  271733878;

		for (var i = 0; i < x.length; i += 16) {
			var olda = a
				, oldb = b
				, oldc = c
				, oldd = d;

			a = ff(a, b, c, d, x[i+ 0], 7 , -680876936);
			d = ff(d, a, b, c, x[i+ 1], 12, -389564586);
			c = ff(c, d, a, b, x[i+ 2], 17,  606105819);
			b = ff(b, c, d, a, x[i+ 3], 22, -1044525330);
			a = ff(a, b, c, d, x[i+ 4], 7 , -176418897);
			d = ff(d, a, b, c, x[i+ 5], 12,  1200080426);
			c = ff(c, d, a, b, x[i+ 6], 17, -1473231341);
			b = ff(b, c, d, a, x[i+ 7], 22, -45705983);
			a = ff(a, b, c, d, x[i+ 8], 7 ,  1770035416);
			d = ff(d, a, b, c, x[i+ 9], 12, -1958414417);
			c = ff(c, d, a, b, x[i+10], 17, -42063);
			b = ff(b, c, d, a, x[i+11], 22, -1990404162);
			a = ff(a, b, c, d, x[i+12], 7 ,  1804603682);
			d = ff(d, a, b, c, x[i+13], 12, -40341101);
			c = ff(c, d, a, b, x[i+14], 17, -1502002290);
			b = ff(b, c, d, a, x[i+15], 22,  1236535329);

			a = gg(a, b, c, d, x[i+ 1], 5 , -165796510);
			d = gg(d, a, b, c, x[i+ 6], 9 , -1069501632);
			c = gg(c, d, a, b, x[i+11], 14,  643717713);
			b = gg(b, c, d, a, x[i+ 0], 20, -373897302);
			a = gg(a, b, c, d, x[i+ 5], 5 , -701558691);
			d = gg(d, a, b, c, x[i+10], 9 ,  38016083);
			c = gg(c, d, a, b, x[i+15], 14, -660478335);
			b = gg(b, c, d, a, x[i+ 4], 20, -405537848);
			a = gg(a, b, c, d, x[i+ 9], 5 ,  568446438);
			d = gg(d, a, b, c, x[i+14], 9 , -1019803690);
			c = gg(c, d, a, b, x[i+ 3], 14, -187363961);
			b = gg(b, c, d, a, x[i+ 8], 20,  1163531501);
			a = gg(a, b, c, d, x[i+13], 5 , -1444681467);
			d = gg(d, a, b, c, x[i+ 2], 9 , -51403784);
			c = gg(c, d, a, b, x[i+ 7], 14,  1735328473);
			b = gg(b, c, d, a, x[i+12], 20, -1926607734);

			a = hh(a, b, c, d, x[i+ 5], 4 , -378558);
			d = hh(d, a, b, c, x[i+ 8], 11, -2022574463);
			c = hh(c, d, a, b, x[i+11], 16,  1839030562);
			b = hh(b, c, d, a, x[i+14], 23, -35309556);
			a = hh(a, b, c, d, x[i+ 1], 4 , -1530992060);
			d = hh(d, a, b, c, x[i+ 4], 11,  1272893353);
			c = hh(c, d, a, b, x[i+ 7], 16, -155497632);
			b = hh(b, c, d, a, x[i+10], 23, -1094730640);
			a = hh(a, b, c, d, x[i+13], 4 ,  681279174);
			d = hh(d, a, b, c, x[i+ 0], 11, -358537222);
			c = hh(c, d, a, b, x[i+ 3], 16, -722521979);
			b = hh(b, c, d, a, x[i+ 6], 23,  76029189);
			a = hh(a, b, c, d, x[i+ 9], 4 , -640364487);
			d = hh(d, a, b, c, x[i+12], 11, -421815835);
			c = hh(c, d, a, b, x[i+15], 16,  530742520);
			b = hh(b, c, d, a, x[i+ 2], 23, -995338651);

			a = ii(a, b, c, d, x[i+ 0], 6 , -198630844);
			d = ii(d, a, b, c, x[i+ 7], 10,  1126891415);
			c = ii(c, d, a, b, x[i+14], 15, -1416354905);
			b = ii(b, c, d, a, x[i+ 5], 21, -57434055);
			a = ii(a, b, c, d, x[i+12], 6 ,  1700485571);
			d = ii(d, a, b, c, x[i+ 3], 10, -1894986606);
			c = ii(c, d, a, b, x[i+10], 15, -1051523);
			b = ii(b, c, d, a, x[i+ 1], 21, -2054922799);
			a = ii(a, b, c, d, x[i+ 8], 6 ,  1873313359);
			d = ii(d, a, b, c, x[i+15], 10, -30611744);
			c = ii(c, d, a, b, x[i+ 6], 15, -1560198380);
			b = ii(b, c, d, a, x[i+13], 21,  1309151649);
			a = ii(a, b, c, d, x[i+ 4], 6 , -145523070);
			d = ii(d, a, b, c, x[i+11], 10, -1120210379);
			c = ii(c, d, a, b, x[i+ 2], 15,  718787259);
			b = ii(b, c, d, a, x[i+ 9], 21, -343485551);

			a = add32(a, olda);
			b = add32(b, oldb);
			c = add32(c, oldc);
			d = add32(d, oldd);
		}
		return [a, b, c, d];
	}
	function hmac(data, key){
		var b = toBin(key);
		if(b.length > 16)
			b=core(b, key.length * charSize);
		var l=new Array(16), r= new Array(16), i = 15;
		for(; i >= 0; i--){
			l[i] = b[i] ^ 0x36363636;
			r[i] = b[i] ^ 0x5c5c5c5c;
		}
		var h=core(l.concat(toBin(data)), 512 + data.length * charSize);
		return core(r.concat(h), 640);
	}

	return {
		"encrypt" : function(s, ot)
		{
			s = core(toBin(s), s.length * charSize);
			//	computes the digest of data, and returns the result as a string of type outputType
			switch(ot)
			{
				case outputTypes.Hex:
					return toHex(s);//	string
				case outputTypes.String:
					return toStr(s);	//	string
				default:
					return toBase64(s);	//	string
			}
		}
		, "hmac" : function(s, key, ot)
		{
			s = hmac(s,key);
			switch(ot)
			{
				case outputTypes.Hex:
					return toHex(s);//	string
				case outputTypes.String:
					return toStr(s);	//	string
				default:
					return toBase64(s);	//	string
			}
		}
		, "outputTypes" : outputTypes
	}
}();